The thermal fatigue behavior of K125 L superalloy at the peak temperature of 1,050 °C was investigated by optical microscope（OM）, X-ray diffraction（XRD）, and scanning electron microscope（SEM）. The experimen...The thermal fatigue behavior of K125 L superalloy at the peak temperature of 1,050 °C was investigated by optical microscope（OM）, X-ray diffraction（XRD）, and scanning electron microscope（SEM）. The experimental results show that the crack initiation sites of tested alloys are at the V-notch tip and the V-notch tip propagates by way of continuous cracking along grain boundaries. The formation of high-temperature oxides and MC carbides accelerates the crack propagation, and no secondary carbides precipitate out. Oxides between cracks are mainly the Al2O3 as well as Cr_2O_3, and carbides are Ta-rich and Tirich MC carbides.展开更多
基金financially supported by the National Natural Science Foundation of China(No.50901077)
文摘The thermal fatigue behavior of K125 L superalloy at the peak temperature of 1,050 °C was investigated by optical microscope（OM）, X-ray diffraction（XRD）, and scanning electron microscope（SEM）. The experimental results show that the crack initiation sites of tested alloys are at the V-notch tip and the V-notch tip propagates by way of continuous cracking along grain boundaries. The formation of high-temperature oxides and MC carbides accelerates the crack propagation, and no secondary carbides precipitate out. Oxides between cracks are mainly the Al2O3 as well as Cr_2O_3, and carbides are Ta-rich and Tirich MC carbides.
